1. Field of the Invention
This invention relates to a fastener-driving tool with a magazine for fasteners, such as U-shaped staples, nails or the like, and a discharge chute, the wall of which, opposite to the outlet of the magazine, is movable from a position closing the discharge chute to a position opening it and vice versa.
2. Description of the Prior Art
With industrial staple or nail-driving tools, which are mainly compressed-air-operated, of the kind described above, frequent interruptions occur because the staples or other fasteners in the discharge chute clog or jam during the driving-in process, driving in of the fasteners being effected by means of a compressed-air-operated piston. One reason for this is that there are some staples which have already been deformed and which cannot be correctly guided out of the discharge chute, and another reason is that there is often unsatisfactory guidance of the staples. Allowance is therefore made for this contingency, and interruptions in working of this kind can normally be quickly and easily overcome.
U.S. Pat. No. 2,985,139 shows a tool in which the wall opposite to the outlet of the magazine includes a flap, which can be swung sideways away from the discharge chute so that the latter is accessible and the removal of jammed fasteners is facilitated. The flap is held in position forming part of the discharge chute with the help of a relatively weak leaf spring. The disadvantages of this arrangement are that, either accurate guidance of the fasteners in the discharge chute will suffer if the spring is too weak, since the flap will swing even with a small force and no longer contribute to precise guidance, or, in order to overcome this disadvantage, the spring must be made so strong that the flap can only be opened by hand by the operator first removing the spring.
Moreover, a fastener-driving tool is shown in German Pat. No. 1,302,136 in which, as with the known tool described above, the wall opposite the outlet of the magazine has been developed as a hinged wall member. This wall member is kept in its closed position with the help of a locking device, which allows the wall member to pivot into an open position under the action of a particular operating force in the direction of feed. By means of this design measure any clogging of the fastener means should be prevented. In practice it has now been shown that the flap mechanism is often operated when not desired, which leads to undesired interruption to the work flow. The insertion of a particular control system, whereby operation of the locking device is only released in the case of an interruption, proves to be impractical. Reliable operation is made even more difficult by changes in the moving components resulting from wear.
Finally, a fastener-driving tool is shown in German Pat. No. 1,171,356 in which the rear wall of the discharge chute is bounded by the base plate of the magazine, which has been produced as an unloader. The base plate is held in its closed position with a resilient fixing element. In smaller machines, with a relatively small driving force, this solution has proved sufficient to overcome the clogged fasteners. However, in machines with a relatively high driving force, efficient working is no longer possible. The power derived from the driving process causes yielding or even opening of the cover plate which moves relative to the base plate of the discharge chute. Through this yielding the feed passage for the fasteners gets bigger and as a result guided passage of the fasteners is more difficult. There is therefore a greater tendency for the fasteners to become multilated or jammed.
The invention therefore has as its object the provision of a fastener-driving tool which guarantees a precise and almost interruption-free passage for the fasteners in the discharge chute and at the same time facilitates rapid removal of clogged or jammed fasteners.